The Study Rheological Behavior of Sunflower Oil

Abstract

Rheology is a simple analysis that is being more and applied to determine the physical behavior of solutions, suspensions and mixtures. The basic parameter, obtained in the rheological study of liquid foods, is viscosity, used to characterize the fluid texture. Rheology is concerned with how materials respond to applied forces and deformations. Basic parameters of stress (force per area) and strain (deformation per length) are key to all rheological evaluations. The sunflower oil was found to be more sensitive to thermal treatment, undergoing greater changes in its properties, especially in viscosity, which may increase considerably. The viscosity of sunflower oil decreases logarithmically with temperature, but the slope representing the change is lessened. Different equations are proposed in literature to calculate the shear stress. The sunflower oil was carefully studied in recent years because they may constitute a raw material for biodegradable lubricants getting organic. These oils are an alternative to synthetic mineral oils. This article presents rheological behavior of sunflower oil. The dynamic viscosity of sunflower oil was determined at temperatures range between 40 – 100ºC and shear rates range from 3.3 – 120 s-1. The between 40 – 70ºC and 100ºC sunflower oil has a Bingham fluid behavior. The between 80 – 90ºC sunflower oil has a Casson fluid behavior.